The basis of the argument being made by Longinus in "On the Sublime," one on which he parted company from most commentators of the classical world on this subject, is that the salient quality of a sublime passage or work is "grandeur of thought" which can only be created by a writer with an "elevated cast of mind." Implied is the notion that such grandeur of thought can only emanate from a person of superior moral character, but also a deep insight into human nature. As he says, unlike rhetoric, the goal of the sublime is not to persuade, but to induce a state of ecstasy in the reader or audience member. A mere knowledge of rhetorical figures, tropes, or other technical tricks, he suggests, will not suffice.
He refers, in Section XI, to various types of the rhetorical figure of amplification ('auxesis'), which includes exaggeration ('hyperbole'), building phrases to a climax ('incrementum') and more, before describing its limits in the absence of sublimity:
In...uses of amplification, if you subtract the element of sublimity, you will, as it were, take the soul from the body. No sooner is the support of sublimity removed, than the whole becomes lifeless, nerveless, and dull.
He draws a clear distinction between the two, in the following section, which would seem to favor the former: "...the sublime is often conveyed in a single thought, but amplification can only subsist with prolixity and diffuseness." In fact, he suggests, the sublime often describes extreme conditions beyond speech, giving as an example, the silence of Ajax, in turning away from Odysseus, in Book XI of The Odyssey. Or in this excerpt from Ode 31 of Sappho:
This, this, is what made my heart
So wildly flutter in my breast;
Whenever I look on thee, my voice
Falters and faints and fails.